Fbank spaulding



(No Model.)

F. SPAULDING.

ADJUSTABLE ANVIL FOB. MIGROMETER GAGES.

Patented Deo. 8, 1885.

UNITED STATES PATENT OEEICE.

FRANK SPAULDING, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE BROWN 8USHARPE MANUFACTURING COMPANY, OF SAME PLACE.

ADJUSTABLE ANViL FOR MICROIVIETER-GAGES.

SPECIFICATION forming part of Letters Patent No. 332.118. dated December8,1885.

Application filed April 9, 1885.

To @ZZ whom t may concern.-

Be it known that I, FRANK SPAULDING, of the city and county ofProvidence, and State of Rhode Island, have invented a new and usefulImprovement in Micrometer-Calipers, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to the adjustable anvils of all kinds ofmicrometer-calipers; and the object of my invention is to avoid acertain defect in such anvils as heretofore constructed.

The purpose of adjustable anvils for micrometer-calipers is tocompensate for wear in the instrument so as to maintain the zeroposition of the sliding scale. This has heretofore been attempted by theuse of an adjustable anvil which rotates throughout its entire length,so that the anvil-face is varied in position with every adjustment.

It has been found very difficult to construct these adjustable anvilswith absolutely true anvil-faces and such imperfection, together withthe effect of wear upon the anvil-face, has rendered the accurateadjustment of the implement exceedingly difficult if not impossible. Inorder to overcome this defect, I cinstruct the adjustable anvils in twoparts, one of which,the face part,has only a simple sliding movement,while the other, the screw part, turns and works in the screw-thread.Thus the anvil-face preserves at all times its original position, and ifthere be any defect in its construction such defect may be readily andaccurately compensated for.

In order that my invention may be fully understood, I will proceed todescribe it with reference to the accompanying drawings, in which-Figurel is a side elevation of a micrometercaliper with my improvementapplied. Fig. 2 is a sectional view of the adjustable anvil and thecontiguous part of the caliper-frame. Figs. 3, 4, and 5 are similarviews showing modified arrangements of the adjustable anvil.

In the said drawings, Fig. l, A designates the caliper-frame,which isU-shaped, having the two arms a a', upon the former of which is mountedascrew-stem, B, threaded through a hollow shank, c, having a scale uponits side. D designates a hollow cap secured rig- Serial No. 161,642. (Nomodel.)

idly upon the outer end of stem B and working over the shank c, theinner end of said.

ment shown, or of any other suitable or preferred form.

Upon the opposite arm a of the frame A is mounted my improved adjustableanvil,which consists of a sliding portion or face part,E, and a rotatingportion or screw part, E. The rotating portion E serves to advance orrecede the sliding portion E in the socket of arm a. In Fig. 2 thisresult is accomplished as follows: The inner end of the face part E isformed with alongitudinal socket, f, having an internal left-handscrew-thread, while the inner, end of screw part E is formed with areduced stein, g, having an external left-hand thread. Through a portionof its length from its outer end the socket'in arm a is formed with aninternal right-hand thread, while the outer surface of the screw part Eis formed with an external right-hand thread. A longitudinal groove, h,is formed upon the outer side of face part E, and in this groove works ascrewpin, h', which is let into the arm a from above.

Thus when the screw part E is turned in one direction the face part Ewill be forced out of the socket, and when the screw part is turned inthe opposite direction the face part will be drawn into the socket, themovements of the face part being performed without its turning, as theopposite screw-threads neutralize each other in this respect.

In Fig. 3 the socket f, stem g, and their screw-threads are employed asin Fig. 2; but the groove h and pin h are dispensed with, the face partE being accurately iitted in the socket of arm a', so that any possibletendency toward turning in the face part E will be prevented byfrictional contact between the face part and the socket. In Fig. 4 thegroove h and pin h are used, as in Fig. 2; but in lieu of the socket fand stem g the inner end of face part E is formed with a circular T-shaped extension, i, which works in a corresponding socket, i', in theinner end of screw part E. In Fig. 5 the arrangement is the same as inIOO Fig. 4:, excepting that the groove h is formed in the socket in arma', while the pin h is i11- serted into face part E. In all of thesearrangements it Will be seen that While the screw-part E turns the facepart E merely slides without any turning movement. Hence if therel beany imperfection in the face or outer end of face part E such defectwill not be constantly varying in position as the adro justable anvil ismanipulated to take up Wear.

Having thus described my invention, I claim as new and desire to secureby Letters Patentl. The combination, with the arm having the graduatedshank and sliding sca-le portions, of the co-operating socketed armpro'- vided with an adjustable anvil consisting of a face partlongitudinally operated in said socket by a screw part connected to saidface part and taking into said socket, for the purpose described.

2. The combination, with the arm having the graduated shank and slidingscale portions, of the co-operating socketed arm provided with anadjustable anvil consisting of a slotted face part longitudinallyoperated in said socket by a screw part connected to said face part andtaking' into said socket having therein a guide-piece, for thepurpose'de' scribed.

3. A micrometer-caliper having a socketed arm provided with anadjustable anvil consisting of a face part longitudinally operated insaid socket by a screw part having two different diameters reverselyscrew-th readed, the

part having one diameter taking into said socket, and the part havingthe other diametertaking into said face part, for the purpose described.

4. A micrometer-caliper having a socketed arm provided with anadjustable anvil consisting of a slotted face part longitudinallyoperated in said socket, which is provided with a guide-piece,v and of ascrew part having two different diameters reversely screwlanvil screwpart E', which has the reverselyscrew-threaded diminished portion g, forthe purpose described.

7. The combination, with the socketed arm a', having the guide-piece h',of the anvil-face,y part E, having the slotjt, and connected to theanvil screw part E', which has the reverselyscrew`threaded diminishedportion g, for the purpose described.

FRANK SPAULDING.

Witnesses:

M. F. BLIGH, J. A. MILLER, J r.

